Package ejava.examples.orm.map

Class ManyManyMapTest

java.lang.Object

ejava.examples.orm.rel.DemoBase

ejava.examples.orm.map.ManyManyMapTest

public class ManyManyMapTest
extends DemoBase

This class demonstrates a Many-to-Many relationship represented as a Map in the owning entity. There are two types of entities represented in these tests. In each case, the foreign key is placed in a link table.

ManyManyInverseEntity to/from OneManyOwningEntity - One end owns the relationship and the other end is the inverse. The inverse side has a reference to the owning side, but the application code (DAO or business logic) is responsible for maintaining the inverse side's reference. ManyManyOwningEntity to ManyManyEntity - since all foreign key information about the relationship is stored in a link/join table, this is almost identical to the case described above except that the non-owning side has no knowledge of the relationship. All this means is that the application code has no responsibility to update the inverse side.

Field Summary

Fields inherited from class ejava.examples.orm.rel.DemoBase

em, emf, logBase, logger

Constructor Summary

Constructors

Constructor	Description
ManyManyMapTest()

Method Summary

Modifier and Type	Method	Description
protected void	cleanup()	This method will cleanup the database of our ManyToMany entities.
protected void	postcleanup()
protected void	precleanup()
void	testManyToManyInverseMap()	This method tests the case where one entity owns the many-to-many, bi-directional relationship and the other side forms the inverse side.
void	XtestManyToManyMap()	This method tests the a simpler version of the owning/inverse case.

Methods inherited from class ejava.examples.orm.rel.DemoBase

setUpBase, setUpDownShared, tearDownBase, tearDownBaseClass

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ManyManyMapTest

public ManyManyMapTest()

Method Detail

precleanup

protected void precleanup()
                   throws Exception

Overrides:

precleanup in class DemoBase

Throws:

Exception

postcleanup

protected void postcleanup()
                    throws Exception

Overrides:

postcleanup in class DemoBase

Throws:

Exception

cleanup

protected void cleanup()
                throws Exception

This method will cleanup the database of our ManyToMany entities. We start with the owning entities, since they own the link/join tables with the foreign keys. Once the associations have been deleted, all inverse and oblivious entities can be safely removed.

Throws:

Exception

testManyToManyInverseMap

public void testManyToManyInverseMap()

This method tests the case where one entity owns the many-to-many, bi-directional relationship and the other side forms the inverse side. If we model the Java form of the relationship without defining a

XtestManyToManyMap

public void XtestManyToManyMap()

This method tests the a simpler version of the owning/inverse case. This case only has an owning side. The final schema ends up looking like the following...

    create table ORMMAP_MANYMANY_ENTITY (
        name varchar(255) not null,
        primary key (name)
    );

    create table ORMMAP_MANYMANY_OWNENTITY (
        name varchar(255) not null,
        primary key (name)
    );

    create table ORMMAP_MANYMANY_OWNENTITY_ORMMAP_MANYMANY_ENTITY (
        ORMMAP_MANYMANY_OWNENTITY_name varchar(255) not null,
        ownedEntities_name varchar(255) not null,
        primary key (ORMMAP_MANYMANY_OWNENTITY_name, ownedEntities_name)
    );